Wear behaviour of ZnAl27/TiCp metal matrix composites under sliding conditions

Abstract

The effect of TiC content on the wear resistance of a Zn–Al alloy was investigated under 300–900 N loads. Sliding tests were carried out to study the wear behaviour of TiCp reinforced ZnAl27 metal matrix composites (MMCs) against AISI type 1050 steel in a block on ring apparatus. The ZnAl27/TiCp MMCs, which were prepared by the addition of 5, 10, and 15 vol.-% TiCp, were produced by powder metallurgy, and the size of particulates was varied at 80, 20, and 5 νm. The powders were uniaxially cold compacted by increasing the pressure up to 250 MPa. Wear tests were carried out in an incremental manner, i.e. 300 m per increment and 1800 m in total. The results of these tests were used to investigate the relationship between weight loss, microstructure, surface hardness, friction coefficient, particle size, and particulate percentage. It was observed that TiCp particulate reinforcement is beneficial in increasing the wear resistance of ZnAl27 alloy, and TiC particulates in MMCs tend to reduce the extent of plastic deformation in the subsurface region of the matrix, thereby delaying the nucleation and propagation of subsurface microcracks.